Taste masked dosage forms and processes for their preparation

ABSTRACT

The invention relates to taste masked dosage forms utilizing low amounts of taste masking polymer, and simple and economical processes for the preparation of the taste masked dosage forms. The taste-masked dosage form includes one or more drugs and one or more cationic polymers synthesized from dimethylaminoethyl methacrylate and neutral methacrylic acid esters. The wt/wt ratio of the drug to polymer is less than about one to two.

FIELD OF THE INVENTION

The technical field of the invention relates to taste masked dosageforms utilizing low amounts of taste masking polymer, and simple andeconomical processes for the preparation of such taste masked dosageforms.

BACKGROUND OF THE INVENTION

Many patients, especially children and elderly, have trouble inswallowing whole tablets and even capsules. It is therefore desirable toadminister drugs to such patients either as a liquid dosage form or as afast dissolving or fast disintegrating solid dosage form. Fastdissolving or disintegrating solid dosage forms, due to their ease ofadministration and pleasant taste, may encourage patients to adhere todaily medication regimens and therefore provide better compliance. Thesedosage forms combine the advantages of both liquid and conventionaltablet formulations, and also offer advantage over both traditionaldosage forms. For example, they provide the convenience of a tabletformulation while also allowing the ease of swallowing provided by aliquid formulation. They also allow the luxury of much more accuratedosing than the primary alternative, oral liquids.

Palatability and “mouth feel” are among the most importantcharacteristics to be considered in providing fast dissolving ordisintegrating solid dosage forms, or matrix, for a drug. Unfortunately,many drugs have a bitter or otherwise unpalatable taste, or anunacceptable mouth feel, which make such drugs unsuitable foradministration as fast dissolving or fast disintegrating dosage forms.Much research has been devoted to designing techniques and approaches tomask the bitter taste of drug in dosage forms. Simple approaches includeadding chemicals mediating, flavoring or sweetening ingredients to thecomposition, which thereby mask the bitterness of the drug. When simpleapproaches are ineffective, drug modifying approaches are used in whichthe dosage form is so formulated that the drug's dissolution in themouth is retarded or prevented by physical and/or chemical means. Onesuch approach to retard by physical means is to embed or encapsulate thedrug within a wall or barrier material that physically separates it fromthe saliva. Cationic copolymers synthesized from dimethylaminoethylmethacrylate and neutral methacrylic acid have been employed as thebarrier material in various taste-masked formulations. In some cases,these polymers are also known to modify taste by chemically interactingwith drugs.

For instance, U.S. Pat. No. 5,286,489 discloses a method of preparingtaste masked dosage forms of active ingredients having an amine or amidogroups by making a porous drug-polymer matrix with Eudragit® E-100. U.S.Pat. No. 5,275,823 discloses a chewable tablet that includes a granulateof a histamine H2-receptor antagonist and Eudragit E® 100, and anadmixture of a taste-masking extragranular water-insoluble hygroscopicexcipient. U.S. Pat. No. 5,489,436 discloses a chewable medicamenttablet that includes a medicament coated with a taste-masking amount ofa polymer blend of dimethylaminoethyl methacrylate and neutralmethacrylic acid esters and a polymer selected from cellulose acetateand cellulose triacetate. U.S. Pat. No. 4,708,867 discloses a minipellet dosage form of prednisone. The dosage form includes a nonpareilseed coated with a first layer of the drug and a second layer of acopolymer of dimethylaminoethyl methacrylate and methyl methacrylate.U.S. Pat. No. 4,760,093 discloses a taste neutral powder form ofspray-dried acetaminophen which includes about 60% to 74% by weightacetaminophen and about 26% to 40% by weight of a copolymer that iscationic in character and is based on dimethylaminoethyl methacrylateand neutral methacrylic acid esters.

U.S. Pat. No. 6,153,220 discloses use of cationic copolymers synthesizedfrom dimethylaminoethyl methacrylate and neutral methacrylic acid estersin amounts significantly greater than the amount of drug in need oftaste masking to form with the drug a taste masked micromatrix powder.The drug and the copolymer (e.g., Eudragit® E 100) are in the form ofmicromatrices having an average size from about 1 μm to 125 μm. The '220patent states that the ratio of copolymer to drug is greater than two toone and that the prior art does not teach the advantageous use ofemploying cationic copolymers synthesized from dimethylaminoethylmethacrylate and neutral methacrylic acid esters in amountssignificantly greater than the amount of drug in need of taste maskingto form with the drug a taste-masked micromatrix powder.

The processes used for taste masking in the patents listed above involvemultiple steps which are technically complicated and difficult toreproduce, besides being economically disadvantageous. Moreover therecommended limit by FDA for oral intake of polymer with adimethylaminoethyl group is quite low and therefore these polymers inpractice cannot be used in higher amounts. Therefore, there still existsa need for taste masked dosage forms utilizing low amounts of cationicpolymers.

SUMMARY OF THE INVENTION

In one general aspect there is provided a taste-masked pharmaceuticaldosage form that includes one or more drugs and one or more cationicpolymers synthesized from dimethylaminoethyl methacrylate and neutralmethacrylic acid esters. The wt/wt ratio of the drug to polymer is lessthan about one to two.

Embodiments of the dosage form may include one or more of the followingfeatures. For example, the wt/wt ratio of the drug to polymer may beless than approximately 1:1.7 or less than approximately 1:1.5.

The drug may be one or more of H₂ receptor antagonists, antibiotics,analgesics, cardiovascular agents, peptides or proteins, hormones,anti-migraine agents, anti-coagulant agents, anti-emetic agents,anti-hypertensive agents, narcotic antagonists, chelating agents,anti-anginal agents, chemotherapeutic agents, sedatives,anti-neoplastics, prostaglandins, drugs for erectile dysfunction, drugsacting on central nervous system, anti-diarrhoeal and anti-diureticagents. The drug may be one or more of nizatidine, cimetidine,ranitidine, famotidine, roxatidine, etinidine, lupitidine, nifentidine,niperitone, sulfotidine, tuvatidine, zaltidine, erythomycin, penicillin,ampicillin, roxithromycin, clarithromycin, psylium, ciprofloxacin,theophylline, nifedipine, prednisone, prednisolone, ketoprofen,acetaminophen, ibuprofen, dexibuprofen lysinate, flurbiprofen, naproxen,codeine, morphine, sodium diclofenac, acetylsalicylic acid, caffeine,pseudoephedrine, phenylpropanolamine, diphenhydramine, chlorpheniramine,dextromethorphan, berberine, mefenamic acid, flufenamic acid,astemizole, terfenadine, phenytoin, guiafenesin, N-acetylprocainamideHCl and pharmaceutically acceptable salts or derivatives thereof.

The drug may be one more unpleasant tasting drugs. The drug may be a lowdose drug and the low dose drug may be one or more of enalapril,lorazepam, zolmitriptan, domperidon, selegiline, ondansetron,mirtazepine, hyosyamine sulphate, risperidone, citalopram, olanzapine,rizatriptan, piroxicam, desloratadine, cetirizine, loperamide,sildenafil, topiramate, and pharmaceutically acceptable salts orderivatives thereof.

The cationic polymer may include a dimethylaminoethyl group. Thecationic polymer may have the following formula:

where: R¹═R³═CH₃

-   -   R²═CH₂CH₂N(CH₃)₂    -   R⁴═CH₃, C₄H₉.        The cationic polymer may be a polymers commercially available as        Eudragit®. The Eudragit® may be one or both of Eudragit® E-100        and Eudragit® EPO.

The taste masked pharmaceutical dosage form may further include otheradditives. The additives may be one or more f cellulose ester, talc,magnesium stearate and pigments. The cellulose ester may be one or moreof cellulose acetate, cellulose acetate butyrate, cellulose triacetate,ethyl cellulose and mixtures thereof.

A drug solution/dispersion may be coated onto a water soluble orinsoluble inert core. The water soluble or insoluble inert core mayinclude one or more of directly compressible dibasic calcium phosphate,directly compressible sugar, microcrystalline cellulose, and nonpareilsugar seeds. The inert core may be directly compressible mannitol. Theinert core may have a particle size greater than about 100 microns.

The dosage form may be one or more of sprinkles, chewable tablets, mouthdissolving tablets, water dispersible tablets, effervescent tablets andsuspensions. The dosage form may further include one or morepharmaceutically inert excipients. The one or more pharmaceuticallyinert excipient may be one or more of diluents, binders, disintegrants,coloring agents, flavoring agents, stabilizers, surfactants, lubricants,glidants, plasticizers and preservatives.

In another general aspect there is provided a process for thepreparation of a taste masked dosage form of one or more unpleasanttasting drugs. The process includes dissolving or dispersing one or moredrugs and one or more cationic polymers in a solvent; and loading asolution and/or dispersion of one or more drugs and one or more cationicpolymer onto an inert core. The wt/wt ratio of the drug to polymer inthe dosage form is less than about one to two. The one or more cationicpolymers are synthesized from dimethylaminoethyl methacrylate andneutral methacrylic acid esters

Embodiments of the process may include one or more of the featuresdescribed above or the following features. For example, the loading ofthe drug solution/dispersion over the inert core may be carried out byone or more of granulation, spray coating or coacervation technique. Thesolvent may include one or more of acetone, methanol, ethyl alcohol,isopropyl alcohol, water, n-butyl alcohol, propylene glycol, ethyleneglycol, monobutyl ether, methyl ethyl ketone, cyclohexanone, methylenechloride, chloroform, carbon tetrachloride, trichloroethylene,tetrachloroethylene, ethyl acetate, n-butyl acetate, propylene glycolacetate, toluene and mixtures thereof. The cationic polymer may includea dimethylaminoethyl group. The cationic polymer may have the followingformula:

where: R¹═R³═CH₃

-   -   R²═CH₂CH₂N(CH₃)₂    -   R⁴═CH₃, C₄H₉.        The cationic polymer may include a polymer commercially        available as Eudragit®. The Eudragit® may be one or both of        Eudragit® E-100 and Eudragit® EPO.

In another general aspect there is provided a taste maskedpharmaceutical dosage form that includes an inert core; one or moredrugs; and one or more cationic polymers. The one or more cationicpolymers are synthesized from dimethylaminoethyl methacrylate andneutral methacrylic acid esters, the one or more drugs and the one ormore cationic polymers form a layer around the inert core, and the wt/wtratio of the drug to polymer in the dosage form is less than about oneto two.

Embodiments of the dosage form may include one or more of the featuresdescribed above or the following features. For example, the cationicpolymer may include a dimethylaminoethyl group. The cationic polymer mayhave the following formula:

where: R¹═R³═CH₃

-   -   R²═CH₂CH₂N(CH₃)₂    -   R⁴═CH₃, C₄H₉.        The cationic polymer may be a polymer commercially available as        Eudragit®. The Eudragit® may be one or both of Eudragit® E-100        and Eudragit® EPO.

The inert core may be one or more of directly compressible dibasiccalcium phosphate, directly compressible sugar, microcrystallinecellulose, and nonpareil sugar seeds.

The details of one or more embodiments of the inventions are set forthin the description below. Other features, objects, and advantages of theinventions will be apparent from the description and the claims.

DETAILED DESCRIPTION OF THE INVENTION

The present invention involves a single step process for the preparationof a taste masked dosage form which requires low amounts of cationicpolymer. Hence, there is provided a taste masked dosage form comprisingunpleasant tasting drug and low amount of cationic polymer. The cationicpolymer may have a dimethylaminoethyl group. In another general aspectthere is provided a process for the preparation of the taste maskeddosage form of unpleasant tasting drug wherein the process includesloading of a solution/dispersion of the drug and the low amount ofcationic polymer on to an inert core. Again, the cationic polymer mayhave a dimethylaminoethyl group. In particular, the weight ratio of theamounts of drug and cationic polymer in the dosage form is less thanabout one to two.

The taste masked dosage forms are prepared by dispersing and/ordissolving one or more drugs and one or more cationic polymers in asolvent and loading this solution or dispersion onto cores. Unlike otherprocesses in which a separated drug coat and polymer coat is used in amulti-step process, the taste masked dosage forms are formed in a singlestep process. Moreover, the quantity of the polymer required to mask theunpleasant taste of the drug is reduced relative to the prior artmulti-step processes, which is not only economical, but also providesbetter maneuverability for other excipients. Further, it provides aphysical polymeric barrier, which completely embeds and/or surrounds thedrug particles unlike in other coating processes in which the particleshape or deposition in a dead zone may not allow complete particlecoating. Further, as the drug and polymer get mixed intimately, itprevents breaking of taste masking coating by mastication. Moreovercomplete solubility of the cationic polymer with a dimethylaminoethylgroup in acidic pH assures complete drug dissolution in the upper gastrointestinal tract.

These drug-loaded cores may be further processed into dosage forms suchas sprinkles, chewable tablets, mouth dissolving tablets, waterdispersible tablets, effervescent tablets and suspensions.

Examples of the therapeutic categories of drugs suitable for the tastemasked dosage form include H₂ receptor antagonists, antibiotics,analgesics, cardiovascular agents, peptides or proteins, hormones,anti-migraine agents, anti-coagulant agents, anti-emetic agents,anti-hypertensive agents, narcotic antagonists, chelating agents,anti-anginal agents, chemotherapy agents, sedatives, anti-neoplastics,prostaglandins, drugs for erectile dysfunction, drugs acting on centralnervous system, anti-diarrhoeal antidiuretic agents, and generally anyother drug for which taste masking is desired.

Specific examples of drugs of the above therapeutic categories includebut are not limited to nizatidine, cimetidine, ranitidine, famotidine,roxatidine, etinidine, lupitidine, nifentidine, niperitone, sulfotidine,tuvatidine, zaltidine, erythomycin, penicillin, ampicillin,roxithromycin, clarithromycin, psylium, ciprofloxacin, theophylline,nifedipine, prednisone, prednisolone, ketoprofen, acetaminophen,ibuprofen, dexibuprofen lysinate, flurbiprofen, naproxen, codeine,morphine, sodium diclofenac, acetylsalicylic acid, caffeine,pseudoephedrine, phenylpropanolamine, diphenhydramine, chlorpheniramine,dextromethorphan, berberine, mefenamic acid, flufenamic acid,astemizole, terfenadine, phenytoin, guiafenesin, N-acetylprocainamidehydrochloride, and pharmaceutically acceptable salts or derivativesthereof.

In particular, low dose drugs such as enalapril, lorazepam,zolmitriptan, domperidon, selegiline, ondansetron, mirtazepine,hyosyamine sulphate, risperidone, citalopram, olanzapine, rizatriptan,piroxicam, desloratadine, cetirizine, loperamide, sildenafil, andtopiramate and pharmaceutically acceptable salts or derivatives thereofmay be used.

Examples of cationic polymers with dimethylaminoethyl groups includevarious grades of polymers commercially available from Rohm Pharma,Germany. In particular, Eudragit® E-100 and Eudragit® EPO may be used.In presence of an acid, Eudragit® E-100 and Eudragit® EPO form watersoluble salts thus providing gastrosoluble film coatings. Eudragit® Efilms swell and are permeable in water and buffer solutions above pH 5and is soluble in gastric fluid below pH 5. The average molecular weightof Eudragit® E is about 150,000 and it neither contains any plasticizersnor requires their addition for processing. The Eudragit® E-100 ispresent in an amount sufficient to mask the otherwise disagreeable tasteof the medicament while in the mouth of the user. The drug to Eudragit®ratio generally is less than or equal to one to two and, in particularis about 1:1.75.

Eudragit®E polymers are methacrylic acid derivatives with adimethylaminoethyl group. According to the fourth addition of theHandbook of Pharmaceutical Excipients, Eudragit E is a cationic polymerbased on dimethylaminoethyl methacrylate and other neutral methacrylicacid esters. It is soluble in gastric fluid as well as in weakly acidicbuffer solutions (up to pH of approximately 5). The structure ofEudragit E is given in the handbook as:

where: R¹═R³═CH₃

-   -   R²═CH₂CH₂N(CH₃)₂    -   R⁴═CH₃, C₄H₉

In one of the embodiments, the taste masked dosage form may furtherinclude other additives such as cellulose esters, talc, magnesiumstearate and pigments which decrease the tendency of the Eudragit®polymer to agglomerate and thereby produce a more uniform surface on thenonpareil seed. Appropriate examples of cellulose esters includecellulose acetate, cellulose acetate butyrate, cellulose triacetate,ethyl cellulose and mixtures thereof.

Examples of suitable inert cores include water soluble and waterinsoluble particles, ideally having a size greater than about 100microns. Specific examples of suitable seeds or cores that may be usedin the dosage forms include inert cores prepared from directlycompressible dibasic calcium phosphate; directly compressible sugar suchas directly compressible mannitol commercially available as PEARLITOL®SD 200 by Roquette Freres S. A., France; microcrystalline cellulose suchas those commercially available as Ethispheres®, made of 100%microcrystalline cellulose and which offers a good alternative forsugar-sensitive users and are available in particle sizes of 200 to 1000micron; and nonpareil sugar seeds marketed by different manufacturersunder different trade names. These are available in different sizesranging from 20 to 2000 microns.

Besides the above materials, the taste masked dosage form may includeone or more pharmaceutically inert excipients such as diluents, binders,disintegrants, coloring agents, flavoring agents, stabilizers,surfactants, lubricants/glidants, plasticizers and preservatives whichare well known in the art of pharmaceutical formulations.

In another embodiment, taste masked dosage forms of unpleasant tastingdrugs may be prepared by preparing a solution and/or dispersion of oneor more unpleasant tasting drug and a low amount of one or more cationicpolymers, optionally with other additives and loading the inert corewith the above solution/dispersion of drug; and forming into a suitabledosage form. Again, the one or more cationic polymers may have adimethylaminoethyl ammonium group

The solution/dispersion of the drug may be loaded over the inert coreusing any conventional technique known in the prior art such asgranulation, spray coating, or coacervation techniques. In particular,the spray coating technique may be used.

Loading of the solution/dispersion of the drug over the inert core by aspray coating technique may be carried out by a process that includesthe steps of dissolving the unpleasant tasting drug and cationic polymerin the solvent and spraying the solution over inert cores in a fluidizedbed coater, such as Glatt Fluid Bed Wurster HS Coater. Air is passedthrough a bed of the inert core particles to fluidize them, and thesolvent solution of the drug-polymer is sprayed onto the fluidized bed.The air passing through the bed dries the loaded core particles. Thedrug loaded cores may then be used in combination with variousexcipients, flavors, and colors to make a chewable, water dispersible ormouth dissolving tablet. These drug loaded cores may also be placed in acapsule to provide sprinkle capsules or may be suspended in suitablesolvent to make suspensions.

Loading by a granulation process may be carried out by conventionaltechniques using a rapid mixer granulator or a fluid bed granulator. Forloading by a coacervation process, homogenizer may be used.

Examples of suitable organic solvents used for the preparation of thesolution/dispersion of drug include acetone, methanol, ethyl alcohol,isopropyl alcohol, water and mixtures thereof. Other examples includen-butyl alcohol, propylene glycol, ethylene glycol, monobutyl ether,methyl ethyl ketone, cyclohexanone, methylene chloride, chloroform,carbon tetrachloride, trichloroethylene, tetrachloroethylene, ethylacetate, n-butyl acetate, propylene glycol acetate, toluene and mixturesthereof.

The following examples further exemplify the inventions and are notintended to limit the scope of the inventions

EXAMPLE 1

Ingredient Quantity (mg) Topiramate 15 Eudragit ® EPO 26 Ethyl cellulose(low viscosity) 3.7 Titanium dioxide 1.0 Nonpareil seeds 45.3 Talc 8.9Isopropyl alcohol/Water (3:1) q.s. Total 100Process:

Weighed quantities of topiramate, Eudragit® EPO and ethyl cellulose weredissolved in a suitable quantity of an isopropyl alcohol/water mixtureto prepare the drug-polymer solution. Talc and titanium dioxide werethen added to the above solution. Nonpareil seeds were placed in a GlattFluid Bed Wurster HS Coater and a drug polymer solution was sprayed onthem. The resulting coated beads were cured by keeping them at roomtemperature for 24 hours. These coated beads were filled into a hardgelatin capsule. The formulation of Example 1 had a ratio of drug(topirimate) to cationic polymer (Eudragit® EPO) of 15 to 26 (i.e., 1 to1.733).

EXAMPLE 2

Ingredient Quantity (mg) Desloratadine 5.05 Eudragit ® E PO 7.50 Ethylcellulose 5.0 Talc 5.0 Isopropyl alcohol q.s. Water q.s. Nonpareil seeds20.0 Total 42.55Process:

Weighed quantities of desloratadine, Eudragit® EPO and ethyl cellulosewere dissolved in a suitable quantity of an isopropyl alcohol/watermixture to prepare the drug-polymer solution. Talc was then added to theabove solution. Nonpareil seeds were placed in a Glatt Fluid Bed WursterHS Coater and the drug-polymer solution was sprayed on them. Theresulting coated beads were cured by keeping them at room temperaturefor 24 hours. These coated beads were filled into a hard gelatincapsule. The formulation of Example 2 had a ratio of drug(desloratadine) to cationic polymer (Eudragit® EPO) of 5.05 to 7.50(i.e., 1 to 1.49).

EXAMPLE 3

Ingredient Quantity (gm) Desloratadine 20.2 Eudragit ® E PO 30.0 Ethylcellulose 20.0 Talc 20.0 Isopropyl alcohol q.s. Water q.s. Nonpareilseeds 80.0 Total 170.20Process:

The process for producing the formulation of Example 3 was the same asthe process used for Example 2. The formulation of Example 3 had a ratioof drug (desloratadine) to cationic polymer (Eudragit® EPO) of 20.2 to30.0 (i.e., 1 to 1.49).

While several particular forms of the inventions have been described, itwill be apparent that various modifications and combinations of theinventions detailed in the text can be made without departing from thespirit and scope of the inventions. Finally, it is contemplated that anysingle feature or any combination of optional features of the inventivevariations described herein may be specifically excluded from theclaimed inventions and be so described as a negative limitation.Accordingly, it is not intended that the inventions be limited, exceptas by the appended claims.

1. A taste-masked pharmaceutical dosage form comprising one or moredrugs and one or more cationic polymers synthesized fromdimethylaminoethyl methacrylate and neutral methacrylic acid esters,wherein the wt/wt ratio of the drug to polymer is less than about one totwo.
 2. The taste masked pharmaceutical dosage form according to claim 1wherein the wt/wt ratio of the drug to polymer is less thanapproximately 1:1.7.
 3. The taste masked pharmaceutical dosage formaccording to claim 1 wherein the wt/wt ratio of the drug to polymer isless than approximately 1:1.5.
 4. The taste masked pharmaceutical dosageform according to claim 1 wherein the drug comprises one or more of H₂receptor antagonists, antibiotics, analgesics, cardiovascular agents,peptides or proteins, hormones, anti-migraine agents, anti-coagulantagents, anti-emetic agents, anti-hypertensive agents, narcoticantagonists, chelating agents, anti-anginal agents, chemotherapeuticagents, sedatives, anti-neoplastics, prostaglandins, drugs for erectiledysfunction, drugs acting on central nervous system, anti-diarrhoeal andanti-diuretic agents.
 5. The taste masked pharmaceutical dosage formaccording to claim 1 wherein the drug comprises one or more ofnizatidine, cimetidine, ranitidine, famotidine, roxatidine, etinidine,lupitidine, nifentidine, niperitone, sulfotidine, tuvatidine, zaltidine,erythomycin, penicillin, ampicillin, roxithromycin, clarithromycin,psylium, ciprofloxacin, theophylline, nifedipine, prednisone,prednisolone, ketoprofen, acetaminophen, ibuprofen, dexibuprofenlysinate, flurbiprofen, naproxen, codeine, morphine, sodium diclofenac,acetylsalicylic acid, caffeine, pseudoephedrine, phenylpropanolamine,diphenhydramine, chlorpheniramine, dextromethorphan, berberine,mefenamic acid, flufenamic acid, astemizole, terfenadine, phenytoin,guiafenesin, N-acetylprocainamide HCl and pharmaceutically acceptablesalts or derivatives thereof.
 6. The taste masked pharmaceutical dosageform according to claim 1 wherein the drug comprises one more unpleasanttasting drugs.
 7. The taste masked pharmaceutical dosage form accordingto claim 1 wherein the drug comprises a low dose drug.
 8. The tastemasked pharmaceutical dosage form according to claim 7 wherein the lowdose drug comprises one or more of enalapril, lorazepam, zolmitriptan,domperidon, selegiline, ondansetron, mirtazepine, hyosyamine sulphate,risperidone, citalopram, olanzapine, rizatriptan, piroxicam,desloratadine, cetirizine, loperamide, sildenafil, topiramate, andpharmaceutically acceptable salts or derivatives thereof.
 9. The tastemasked pharmaceutical dosage form according to claim 1 wherein thecationic polymer includes a dimethylaminoethyl group.
 10. The tastemasked pharmaceutical dosage form according to claim 1 wherein thecationic polymer has the following formula:

where: R¹═R³═CH₃ R²═CH₂CH₂N(CH₃)₂ R⁴═CH₃, C₄H₉.
 11. The taste maskedpharmaceutical dosage form according to claim 1 wherein the cationicpolymer comprises a polymers commercially available as Eudragit®. 12.The taste masked pharmaceutical dosage form according to claim 11wherein the Eudragit® comprises one or both of Eudragit® E-100 andEudragit® EPO.
 13. The taste masked pharmaceutical dosage form accordingto claim 12 wherein the Eudragit® comprises Eudragit® E-100.
 14. Thetaste masked pharmaceutical dosage form according to claim 12 whereinthe Eudragit® comprises Eudragit® EPO.
 15. The taste maskedpharmaceutical dosage form according to claim 1 wherein the dosage formfurther comprises other additives.
 16. The taste masked pharmaceuticaldosage form according to claim 15 wherein the additives comprise one ormore f cellulose ester, talc, magnesium stearate and pigments.
 17. Thetaste masked pharmaceutical dosage form according to claim 16 whereinthe cellulose ester comprises one or more of cellulose acetate,cellulose acetate butyrate, cellulose triacetate, ethyl cellulose andmixtures thereof.
 18. The taste masked pharmaceutical dosage formaccording to claim 1 wherein a drug solution/dispersion is coated onto awater soluble or insoluble inert core.
 19. The taste maskedpharmaceutical dosage form according to claim 18 wherein the watersoluble or insoluble inert core comprises one or more of directlycompressible dibasic calcium phosphate, directly compressible sugar,microcrystalline cellulose, and nonpareil sugar seeds.
 20. The tastemasked pharmaceutical dosage form according to claim 19 wherein theinert core comprises directly compressible mannitol.
 21. The tastemasked pharmaceutical dosage form according to claim 18 wherein theinert core has a particle size greater than about 100 microns.
 22. Thetaste masked pharmaceutical dosage form according to claim 1 wherein thedosage form is selected from the group consisting of sprinkles, chewabletablets, mouth dissolving tablets, water dispersible tablets,effervescent tablets and suspensions.
 23. The taste maskedpharmaceutical dosage form according to claim 1 wherein the dosage formfurther comprises one or more pharmaceutically inert excipients.
 24. Thetaste masked pharmaceutical dosage form according to claim 23 whereinthe one or more pharmaceutically inert excipient comprise one or more ofdiluents, binders, disintegrants, coloring agents, flavoring agents,stabilizers, surfactants, lubricants, glidants, plasticizers andpreservatives.
 25. A process for the preparation of a taste maskeddosage form of one or more unpleasant tasting drugs, the processcomprising: dissolving or dispersing one or more drugs and one or morecationic polymers in a solvent; and loading a solution and/or dispersionof one or more drugs and one or more cationic polymer onto an inert corewherein the one or more cationic polymers are synthesized fromdimethylaminoethyl methacrylate and neutral methacrylic acid esters andthe wt/wt ratio of the drug to polymer in the dosage form is less thanabout one to two.
 26. The process according to claim 25 wherein theloading of the drug solution/dispersion over the inert core is carriedout by one or more of granulation, spray coating or coacervationtechnique.
 27. The process according to claim 25 wherein the loading ofthe drug solution/dispersion over the inert core is carried out by spraycoating.
 28. The process according to claim 25 wherein the loading ofthe drug solution/dispersion over the inert core is carried out bygranulation.
 29. The process according to claim 25 wherein the loadingof the drug solution/dispersion over the inert core is carried out bycoacervation.
 30. The process according to claim 25 wherein the solventcomprises one or more of acetone, methanol, ethyl alcohol, isopropylalcohol, water, n-butyl alcohol, propylene glycol, ethylene glycol,monobutyl ether, methyl ethyl ketone, cyclohexanone, methylene chloride,chloroform, carbon tetrachloride, trichloroethylene,tetrachloroethylene, ethyl acetate, n-butyl acetate, propylene glycolacetate, toluene and mixtures thereof.
 31. The process according toclaim 25 wherein the cationic polymer includes a dimethylaminoethylgroup.
 32. The process according to claim 25 wherein the cationicpolymer has the following formula:

where: R¹═R³═CH₃ R²═CH₂CH₂N(CH₃)₂ R⁴═CH₃, C₄H₉.
 33. The processaccording to claim 25 wherein the cationic polymer comprises a polymercommercially available as Eudragit®.
 34. The process according to claim25 wherein the Eudragit® comprises one or both of Eudragit® E-100 andEudragit® EPO.
 35. A taste masked pharmaceutical dosage form comprising:an inert core; one or more drugs; and one or more cationic polymers,wherein one or more cationic polymers are synthesized fromdimethylaminoethyl methacrylate and neutral methacrylic acid esters, theone or more drugs and the one or more cationic polymers form a layeraround the inert core, and the wt/wt ratio of the drug to polymer in thedosage form is less than about one to two.
 36. The taste maskedpharmaceutical dosage form according to claim 35 wherein the cationicpolymer includes a dimethylaminoethyl group.
 37. The taste maskedpharmaceutical dosage form according to claim 35 wherein the cationicpolymer has the following formula:

where: R¹═R³═CH₃ R²═CH₂CH₂N(CH₃)₂ R⁴═CH₃, C₄H₉.
 38. The taste maskedpharmaceutical dosage form according to claim 35 wherein the cationicpolymer comprises a polymer commercially available as Eudragit®.
 39. Thetaste masked pharmaceutical dosage form according to claim 35 whereinthe Eudragit® comprises one or both of Eudragit® E-100 and Eudragit®EPO.
 40. The taste masked pharmaceutical dosage form according to claim35 wherein the inert core comprises one or more of directly compressibledibasic calcium phosphate, directly compressible sugar, microcrystallinecellulose, and nonpareil sugar seeds.